DE-A-749 281 shows a cutter head that is retained on a tractor by means of a latching arrangement that releases upon an impact with an obstacle, in that it unlatches. The cutter head then pivots in the horizontal direction about a vertical journal to the rear.
CH-A5-674 440 shows an arrangement for fastening a cutter head to a vehicle. This arrangement is provided with a hinged joint that includes a shear pin. This shear pin can shear off upon impact of the cutter head with an obstacle, whereupon the cutter head can pivot to the rear about a vertical axis.
The problem underlying the invention is seen in the fact that retaining arrangements of this type permit an evasion of the operating unit only to the rear and therefore are not appropriate for an operating unit arranged in a side region of a vehicle, particularly since in such a movement, a relatively large space must be covered and collisions with further obstacles or with wheels of a vehicle of a corresponding configuration can occur.